For quite a number of years, data including voice, video and other information have been converted to digital form and transferred over digital networks from content providers to the users or subscribers. The most obvious example of this “digital conversion” of voice, video, and other data can be seen in the world-wide-web (WWW) or Internet. As digital content becomes more rich and complex, the required size of the data transfers have increased from kilobytes to megabytes and, further, to gigabytes. Hence, there is a need for greatly increased data access speeds between content producers and/or providers and consumers and/or end users.
Currently most businesses and residences use hardwired connections from either a local telecommunications provider, also known as a Local Exchange Carrier (LEC) or from a local cable network provider, also known as a Multi-System Operator (MSO). Certain businesses and residences also receive video and other data from direct broadcast satellites (DBS).
LECs primarily use circuit-switched networks to provide voice and data connections to customers with data rate of 64 kb/s for single line, 1.544 Mb/s for a T-1, and 44.736 Mb/s for a T-3 line.
Certain regional Bell operating companies (RBOC) have begun laying fiber optic cables directly to, or in close proximity to, commercial buildings and residences to allow for increased speeds and reduced operating costs. This is generally referred to as fiber to the premise (FTTP). These newer fiber optic systems are sometimes passive optical networks (PON) where there are no active devices between the final endpoint and the head end where all the fibers terminate. The distance from an aggregation point to an endpoint can be tens of kilometers. To reduce the total number of fibers required, these networks typically use wavelength division multiplexing (WDM) to split one “feeding” fiber with a number of endpoints.
PON networks are designed to carry voice, video and other data traffic bi-directionally from an aggregation point or head end to an endpoint. The networks are typically set up for asymmetric data flow where more data is transmitted from the aggregation pint to the endpoint (downstream) than from the endpoint to the aggregation point (upstream). End user data speeds are typically 5-30 Mb/s downstream and 1-15 Mb/s upstream.
MSOs typically utilize hybrid fiber and coax (HFC) plants to send voice, video and other data to customer endpoints. These systems bring digitized voice, video and other data over one or more fiber optic cables that are tens of kilometers in length to a fiber node (FN). The data is typically converted to analog RF or digital data, e.g., Quadrature Amplitude Modulated (QAM) encoded digital data, and relayed to commercial and residential premises. The FN typically serves about 500 endpoints, but the capacity can vary from less than 100 to over 1000. The video signal is converted to both analog and digital RF for reception by a cable-ready television or set-top box. The voice and other data signals are transmitted using the data over cable system interface specification (DOCSIS) to and from a cable modem. MSOs typically transfer data in an asymmetric manner in their networks. For example, DOCSIS data rates typically range from 1-10 Mb/s for downstream communications and 0.25-2 Mb/s upstream communications. FIG. 1A is conceptual block diagram of a portion of a prior art cable TV network downstream of a fiber node.
DBS networks typically use one or more satellites in geostationary orbit to broadcast video and certain other data to small dish receivers. While DBS networks can transmit data in a bidirectional manner, the capacity is typically limited to less then 1.5 Mb/s downstream and less than 0.5 Mb/s upstream. In addition to the relatively slow data rates, there is considerable latency incurred because of the round trip time from geostationary orbit. With this latency, real time games and voice communications are not practical.
The physical links to homes and businesses in certain regions are predominantly twisted-pair copper lines for telecommunications and coaxial cable for video data. The current LEC and MSO infrastructure does not have the capability or capacity to meet the future bandwidth requirements needed for multimedia data services that combine voice, video and other forms of data. While certain telecommunications providers are performing FTTP infrastructure upgrades to address the problem of limited data bandwidth, cost of such an upgrade is unacceptably high.
Accordingly, there is a need to significantly improve data rates and/or data bandwidth to business, residential customers, and/or end users using existing cable and/or telecommunications infrastructure.